The present invention relates to a tie plate manipulator vehicle and associated method of using the vehicle to apply and/or remove tie plates from between the underside of rails and the top surface of railroad cross ties.
It is often necessary to replace some railroad ties in an existing railroad track. Various machines are used as part of this process.
A spike puller machine pulls spikes which hold tie plates to the cross ties of the railroad track. The spikes may be processed for reuse manually or, more preferably, by using the present inventor's rail spike cleaning apparatus described in U.S. Pat. No. 4,940,001 issued Jul. 10, 1990 and hereby incorporated by reference. Those ties which are to be replaced and which have anchors adjacent to them must have the anchors spread away from the ties. This may advantageously be accomplished by using the present inventor's anchor spreader apparatus as described in U.S. Pat. No. 4,903,611 issued on Feb. 27, 1990 and hereby incorporated by reference. The general process next would include removal of the tie by using one of various known machines slide the tie out from under the rails. Since the tie plates are no longer fastened to the ties by the previously removed spikes, the tie plates are usually manually placed on ties which are adjacent to the ties which must be removed. A tie inserter machine (might be the same machine as the tie remover) inserts a new tie underneath the rails.
After insertion of the new tie, a ballast sweeper or broom machine having a rotary core and various sweeper elements is used to sweep ballast (the rock, usually limestone, used for the roadbed) off the top of the newly inserted tie. After the newly inserted tie or ties have been swept clean, a vehicle having a rail lifter is used to lift the rails up and away from the newly inserted tie, whereupon the tie plates, previously placed manually adjacent to the location of the tie being replaced, are manually placed underneath the rails and on the top surface of the newly inserted tie. The rail lifter or lifters then release the rails such that they drop into the rail receiving portions of the tie plates. Next, a spiker vehicle would be used to insert new or reclaimed spikes into the spike holes of the tie plates on the new tie.
Although the known technique generally works, it is subject to a number of disadvantages. In particular, the requirement for manually inserting the tie plates under the rails adds significant labor costs to the overall operation. Depending upon the care of the workers and the reliability of the rail lifter, manual insertion of the tie plates under the lifted rail may raise safety concerns. In order to accomplish the manual placement of tie plates under the rails, one worker is usually used on each side of the railroad track. Depending upon the reliability of the two workers and their energy level, the efficiency and time required to replace the tie plates varies significantly.
In addition to the requirement for the laborers to manually place the tie plates under the rails after the new tie is inserted, the generally used technique requires laborers to collect or remove tie plates from a tie which is being replaced. Again, this is physically demanding work which adds significantly to the overall labor cost of the tie replacement process.